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2005 Fiscal Year Final Research Report Summary

Research on the Formation and Activity of Galactic Nuclear Gas Disks Including Magnetohydrodynamical Processes

Research Project

Project/Area Number 16340052
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Astronomy
Research InstitutionChiba University

Principal Investigator

MATSUMOTO Ryoji  Chiba University, Faculty of Science, Professor, 理学部, 教授 (00209660)

Co-Investigator(Kenkyū-buntansha) HANAWA Tomoyuki  Chiba University, Center for Frontier Science, Professor, 先進科学研究教育センター, 教授 (50172953)
MIYAJI Shigeki  Chiba University, Graduate School of Science and Technology, Associate Professor, 大学院・自然科学研究科, 助教授 (10157646)
YOKOYAMA Takaaki  University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (00311184)
FUKUDA Naoya  Okayama University of Science, Faculty of Infomatics, Instructor, 総合情報学部, 講師 (90368613)
Project Period (FY) 2004 – 2005
KeywordsGalactic Disk / Accretion Disk / Magnetohydrodynamics / Numerical Simulation / Active Galactic Nuclei / Astrophysical Jets / Self Gravity / Galactic Dynamo
Research Abstract

Three-dimensional global magnetohydrodynamic (MHD) simulations have been carried out to study the mechanism of the formation and activity of galactic nuclear gas disks. The initial state is a gas torus threaded by weak toroidal magnetic fields. We assumed that the gas torus is rotating in the gravitational potential of stars and the dark matter. We found (1) magnetorotational instability growing in the torus drives magnetic turbulence, (2) interstellar gas in falls by transporting angular momentum through Maxwell stress and forms a nuclear gas disk, (3) galactic mean magnetic fields are amplified up to 1 micro G, (4) the direction of mean azimuthal magnetic fields reverses with period of about 1Gyr, and (5) the reversal of mean magnetic fields is driven by the buoyant escape of magnetic flux from the gas disk to the galactic halo. We also carried out global 3D MHD simulations of the nuclear gas disk and found that magnetic loops similar to those observed inside 1kpc of our galaxy are formed by the buoyant rise of the magnetic flux from the gas disk.
Numerical simulations indicated that poloidal magnetic flux is carried toward the galactic center. We performed 2D and 3D global resistive MHD simulations of jet formation from disks threaded by vertical magnetic fields and showed that mass accretion is partly driven by the angular momentum extraction by jets. The stability of magnetically driven jets has been studied by using 3D MHD code in Cartesian coordinates. We found that although the kink instability grows in regions where magnetic field lines are strongly twisted, it does not disrupt the jet.
We implemented 3D MHD simulation engine based on the Roe scheme to the MHD simulator CANS (Coordinated Astronomical Numerical Software). The manuals and web-pages of CANS have been translated into English and used in the Asian Winter School on Numerical Astrophysics, held in March 13-17, 2006, at Chiba University.

  • Research Products

    (30 results)

All 2006 2005 2004

All Journal Article (30 results)

  • [Journal Article] Formation of Magnetically Supported Disks during Hard-to-Soft Transitions in Black Hole Accretion Flows2006

    • Author(s)
      Machida, M
    • Journal Title

      Publications of the Astronomical Society of Japan 58

      Pages: 193-202

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Global Three-dimensional MHD Simulations of Galactic Gaseous Disks : I. Amplification of Mean Magnetic Fields In Axisymmetric Gravitational Potential2006

    • Author(s)
      Nishikori, H
    • Journal Title

      Astrophysical Journal 641

      Pages: 862-877

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Formation of Magnetically Supported Disks during Hard-to-Soft Transitions in Black Hole Accretion Flows2006

    • Author(s)
      Machida, M.
    • Journal Title

      Publications of the Astronomical Society of Japan 58

      Pages: 193-202

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Global Three-dimensional MHD Simulations of Galactic Gaseous Disks : I. Amplification of Mean Magnetic Fields in Axisymmetric Gravitational Potential2006

    • Author(s)
      Nishikori, H.
    • Journal Title

      Astrophysical Journal 641

      Pages: 862-877

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] 宇宙プラズマにおける磁気エネルギー解放現象のシミュレーション2005

    • Author(s)
      松元亮治
    • Journal Title

      電気学会誌 125

      Pages: 21-24

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] The Acceleration Mechanism of Resistive Magnetohydro dynamic Jets Launched from Accretion Disks2005

    • Author(s)
      Kuwabara, T
    • Journal Title

      Astrophysical Journal 621

      Pages: 921-931

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Global Three-Dimensional MHD Simulations of Co-existence of Hard State and Soft State Disks in Black Hole Accretion Flows2005

    • Author(s)
      Machida, M
    • Journal Title

      In Growing black holes : accretion in a cosmological context, ed. A. Merloni, S. Nayakshin, R. A. Sunyaev

      Pages: 309-310

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Magnetohydrodynamic Simulations of the Wiggle Instability in Spiral Galaxies2005

    • Author(s)
      Tanaka, M
    • Journal Title

      AIP Conference Proceedings 784

      Pages: 792-797

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Global Three-Dimensional MHD Simulations of Galactic Gaseous Disks2005

    • Author(s)
      Nishikori, H
    • Journal Title

      AIP Conference Proceedings 784

      Pages: 786-791

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Network Laboratory System for Space Simulations2005

    • Author(s)
      Matsumoto, R
    • Journal Title

      Proceedings of 7^th International School/Symposium for Space Simulations

      Pages: 159-162

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] 熱的に不安定な降着円盤の3次元磁気流体数値実験2005

    • Author(s)
      松元亮治
    • Journal Title

      日本流体力学会年会2005 講演論文集 24巻別冊

      Pages: 108-108

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] 降着円盤から噴出する磁気流体ジェットの安定性2005

    • Author(s)
      桑原匠史
    • Journal Title

      日本流体力学会年会2005 講演論文集 24巻別冊

      Pages: 109-109

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] HLL法に基づいた相対論的MHDコードの開発2005

    • Author(s)
      淺野栄治
    • Journal Title

      日本流体力学会年会2005 講演論文集 24巻別冊

      Pages: 112-112

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Numerical Simulations of Magnetic Energy Release in Astrophysical Plasma2005

    • Author(s)
      Matsumoto, R
    • Journal Title

      The Journal of the Institute of Electrical Engineers of Japan 125

      Pages: 21-24

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] The Acceleration Mechanism of Resistive Magnetohydrodynamic Jets Launched from Accretion Disks2005

    • Author(s)
      Kuwabara, T.
    • Journal Title

      Astrophysical Journal 621

      Pages: 921-931

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Global Three-Dimensional MHD Simulations of Co-existence of Hard State and Soft State Disks in Black Hole Accretion Flows2005

    • Author(s)
      Machida, M.
    • Journal Title

      In Growing black holes : accretion in a cosmological context (ed. A.Merloni, S.Nayakshin, R.A.Sunyaev)

      Pages: 309-310

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Magnetohydrodynamic Simulations of the Wiggle Instability in Spiral Galaxies2005

    • Author(s)
      Tanaka, M.
    • Journal Title

      AIP Conference Proceedings 784

      Pages: 792-797

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Global Three-Dimensional MHD Simulations of Galactic Gaseous Disks2005

    • Author(s)
      Nishikori, H.
    • Journal Title

      AIP Conference Proceedings 784

      Pages: 786-791

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Network Laboratory System for Space Simulations2005

    • Author(s)
      Matsumoto, R.
    • Journal Title

      Proceedings of 7^<th> International School/Symposium for Space Simulations

      Pages: 159-162

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Three-dimensional MHD Simulations of Thermally Unstable Accretion Disks2005

    • Author(s)
      Matsumoto, R.
    • Journal Title

      Proceedings of 2005 Annual Meeting, Japan Society of Fluid Mechanics

      Pages: 108

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] The Stability Analysis of MHD Jets Emanating from Accretion Disks2005

    • Author(s)
      Kuwabara, T.
    • Journal Title

      Proceedings of 2005 Annual Meeting, Japan Society of Fluid Mechanics

      Pages: 109

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Developments of a Relativistic Magnetohydrodynamic Code Based on HLL Scheme2005

    • Author(s)
      Asano, E.
    • Journal Title

      Proceedings of 2005 Annual Meeting, Japan Society of Fluid Mechanics

      Pages: 112

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Linear Analysis of Parker-Jeans Instability with Cosmic-Ray2004

    • Author(s)
      Kuwabara, T
    • Journal Title

      Journal of the Korean Astronomical Society 37

      Pages: 601-603

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] 渦状銀河におけるスパー構造形成の磁気流体数値実験2004

    • Author(s)
      田中 実
    • Journal Title

      日本流体力学会年会2004 講演論文集

      Pages: 592-593

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] 光学的に薄いブラックホール降着円盤の3次元MHD数値実験 : 輻射冷却の効果2004

    • Author(s)
      町田真美
    • Journal Title

      日本流体力学会年会2004 講演論文集

      Pages: 604-605

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] 降着円盤から噴出する準定常ジェット形成の散逸性磁気流体数値実験2004

    • Author(s)
      松元亮治
    • Journal Title

      日本流体力学会年会2004 講演論文集

      Pages: 606-607

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Linear Analysis of Parker-Jeans Instability with Cosmic-Ray2004

    • Author(s)
      Kuwabara, T.
    • Journal Title

      Journal of the Korean Astronomical Society 37

      Pages: 601-603

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Magnetohydrodynamic Simulations of the Formation of Spur Structures in Spiral Galaxies2004

    • Author(s)
      Tanaka, M.
    • Journal Title

      Proceedings, 2004 Meeting of Japan Society of Fluid Mechanics

      Pages: 592-593

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Global Three-dimensional Simulations of Black Hole Accretion Disks : Effect of Radiative Cooling2004

    • Author(s)
      Machida, M.
    • Journal Title

      Proceedings, 2004 Meeting of Japan Society of Fluid Mechanics

      Pages: 604-605

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Resistive Magnetohydrodynamic Simulations of Formation of Quasi-steady Jets from Accretion Disks2004

    • Author(s)
      Matsumoto, R
    • Journal Title

      Proceedings, 2004 Meeting of Japan Society of Fluid Mechanics

      Pages: 606-607

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 2007-12-13  

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